Antimony Concentration Limitation in Dislocation-Free CZ Silicon Crystals

Abstract

The maximum antimony concentration can be incorporated in a 150 mm Si͑100͒ crystal using the Czochralski ͑CZ͒ crystal growth method was investigated. The antimony limitation was found to be about 5.96 ϫ 10 18 atom/cm 3 ͑0.0084 ⍀ cm͒ using a charge size of 45,000 g. It was limited by the occurrence of constitutional supercooling in the center of the crystal. A ripple or instability in the solid/melt interface was observed in the center of the crystal at the onset of constitutional supercooling. Cellular growth structure was observed when the ripple reached a critical magnitude of 0.027 cm in the growth direction. When cellular growth occurred, cellular structure formed and dislocation networks were found in the boundaries of the cells. The melt temperature gradient at the solid/melt interface was calculated to be about 9.86°C/cm.

Constitutional Supercooling in Czochralski Growth οf Heavily Doped Silicon Crystals

“…[6,12,15]. Therefore, it will remain dicult to prove in a certain case whether constitutional supercooling is responsible for a structure loss or whether other phenomena were limiting the dislocation-free growth of heavily doped silicon crystals by the Czochralski technique.…”

Growth and characterization of heavily doped silicon crystals

“…Boron represents the best case, since it has the highest segregation coefficient (k o =0.8-0.73) among all common dopants (see table 1) [3]. The worst case is that of antimony, which has the lowest segregation coefficient (k o =0.023) and for which the lowest resistivity achievable without dislocations has been reported to be around 8.4 mΩ·cm [4]. Phosphorus and arsenic are in an intermediate situation, having a segregation coefficient of 0.35 and 0.3, respectively.…”

Edge facet dynamics during the growth of heavily doped n-type silicon by the Czochralski-method

“…It was statistically observed that the dislocations form more frequently during the growth of heavily n-type doped crystals (>1x10 19 dopants/cm 3 ) than during the growth of heavily p-type or not heavily doped silicon [6][7][8][9][10]. Furthermore, it was found that dislocation formation in such heavily n-type doped Si crystals takes place more often during the growth stage of the top cone [11] and also its shape affects the risk for dislocation generation [12; 13]: The risk grows with increasing taper angle of the top cone.…”